JPH04318231A - Turbine duct mounting structure for gas-turbine engine - Google Patents

Abstract

PURPOSE:To prevent a turbine duct and a turbine rotor from coming into contact with each other even if thermal strain occurs in a turbine nozzle by temperature difference at the operating time of a gas turbine engine in the mounting structure of the turbine duct for gas turbine engine. CONSTITUTION:A turbine nozzle 6 and a turbine duct 21 are separated from each other, and the turbine nozzle 6 is fixed on a compressor body 4 side and the turbine duct 21 is fixed on an exhaust diffuser 19 which is on the engine body side respectively. They are made to come into elastic contact with each other for engagement through a leaf spring 13 and a piston ring 22. Therefore, thermal strain of the turbine nozzle 6 is absorbed in the displacement of the leaf spring 13 and the piston ring 22, so that the thermal strain has no influence upon the turbine duct 21.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine engine, and more particularly to a mounting structure for a turbine duct of a turbine rotor driven by combustion gas generated in a combustor.

0002

BACKGROUND OF THE INVENTION In recent years, a gas turbine engine generates power by introducing high-pressure air from a compressor into a combustor and burning it, and then blowing the combustion gas against a turbine rotor to rotate a turbine. It is also attracting attention as an internal combustion engine for driving vehicles.

FIG. 4 shows a cross section of a compressor turbine portion of a typical two-shaft gas turbine engine. In this figure, 41 is a turbine rotor driven by combustion gas, and its power drives a compressor (not shown) located on the left side of the figure. Further, in the vicinity of this turbine rotor 41,
A turbine nozzle 43 including a large number of nozzle blades 42 arranged circumferentially is provided on the upstream side in the flow direction of the combustion gas.

Furthermore, the turbine nozzle 43 integrally includes, in addition to the nozzle blades 42, an outer circumferential ring 44 located on the outside thereof and an inner circumferential ring 45 on the inner side, and a flange extending inward from the inner circumferential ring 45. It is fixed to the compressor main body 47 side via 46.
1-92729).

[0005]

In the conventional gas turbine engine described above, as shown in FIG. 4, the outer circumferential ring 44 of the turbine nozzle 43 extends further downstream than the nozzle blade 42 in the combustion gas flow direction, and the outer ring 44 of the turbine nozzle 43 extends further downstream from the nozzle blade 42 in the combustion gas flow direction. It also functions as a turbine duct surrounding 41,
The end of the outer peripheral ring 44 on the downstream side of the combustion gas extends radially outward with the turbine rotor axis as the center, and the scroll 4
8 is also integrally provided with a circumferential flange 49.

By the way, during engine operation when high-temperature, high-pressure combustion gas flows through the turbine nozzle 43 and the turbine rotor 41 to the engine main body side, it actually flows through the turbine nozzle inlet (near the combustion gas outlet of the scroll 48), There is a temperature difference between the turbine nozzle outlet (downstream side of the turbine rotor 41), and the degree of expansion on the turbine nozzle inlet side is larger than the degree of expansion on the turbine duct side, and while the nozzle inlet side is expanded, the outlet side is expanded. It becomes a narrowed shape.

Therefore, in the case of the turbine nozzle 43 that also functions as a turbine duct, as in the conventional gas turbine engine described above, the inner wall of the outer circumferential ring 44 is inclined toward the turbine blade side of the turbine rotor 41. This may cause contact with the turbine blades.

[0008] The present invention has been provided in view of the above problems, and has a structure in which the turbine duct does not come into contact with the turbine rotor even if such a temperature difference occurs, and smooth rotation of the turbine rotor is guaranteed. The purpose of this invention is to provide a turbine duct mounting structure for a gas turbine engine.

[0009]

[Means for Solving the Problems] To achieve the above object, the present invention provides a turbine nozzle disposed close to a turbine rotor of a gas turbine engine and upstream of combustion gas thereof, and a turbine duct surrounding the turbine rotor. A gas turbine engine is provided, in which the turbine nozzle is fixed to the compressor main body side, the turbine duct is fixed to the engine main body side, and the turbine nozzle and the turbine duct are brought into contact engagement via elastic means. A turbine duct mounting structure is provided.

0010

[Operation] Separates the turbine duct from the turbine nozzle,
Since both parts are fixed to separate parts, the thermal strain of the turbine nozzle does not directly displace the turbine duct, and the thermal strain itself is absorbed by the elastic means provided between the two parts.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show a cross section and a partially enlarged view of a turbine section (more specifically, a compressor turbine section) of a two-shaft gas turbine engine as an embodiment of the present invention, and 1 shows a turbine blade. 2, which is rotatably supported by a bearing housing 5 of a compressor main body 4 via a bearing 3.

Further, a turbine nozzle 6 is fixed to the bearing housing 5 with a plurality of bolts 7 (only one is shown in the figure). This turbine nozzle 6 includes a plurality of nozzle blades 8 arranged in the circumferential direction as fixed blades, an outer circumferential ring 9 located on the outer circumferential side, and an inner circumferential ring 1 located on the inner circumferential side.
0 and a curved flange 11 extending further inward than the inner circumferential ring 10, and the nozzle blade 8 thereof is arranged adjacent to the turbine blade 2 described above.

According to this embodiment, the outer circumferential ring 9 of the turbine nozzle 6 further includes a circumferential flange 1 outwardly.
2 is formed, and a ring-shaped leaf spring 13 is formed as an elastic means.
are joined. Further, at the end of this leaf spring 13, a turbine blade 2 is located at approximately the same axial position as the turbine rotor 1.
A wide annular member 14 is joined to circumferentially surround.

An adapter 16 for assisting connection with the turbine nozzle 6 is provided at the gas outlet portion of the scroll 15 that guides combustion gas from a combustor (not shown) to the turbine rotor 1. tightly fitted. Furthermore, a curved plate 17 made of an elastic material is joined to this adapter 16, and its bead portion 17a
is in contact with the outer peripheral surface of the annular member 14, and the annular member 1
4 is supported from the outside. In this embodiment, the scroll 15 is connected to an insulator (heat-insulating material) 18 that surrounds the bearing housing 5 via this adapter 16.
The insulator 18 is further fixed to the compressor body 4.

After driving the turbine rotor 1, the combustion gas flows into the exhaust diffuser 19 and flows toward the engine body. According to this embodiment, the combustion gas flows into the exhaust diffuser 19, which constitutes a part of the engine body. Ring plate 2
The turbine duct 21 is fixed through 0.

The turbine duct 21 is inserted inside the annular member 14 and is formed as a ring-shaped member in which the turbine blade 2 is rotatably housed. A sealing piston ring 22 (which also corresponds to the elastic means of the present invention) is attached to the inner circumferential wall of the annular member 14 to prevent gas leakage through the gap between the annular member 14 and the turbine duct 21 .

A second ring-shaped plate 23 made of an elastic material is further joined to the exhaust diffuser 19 so as to surround the ring-shaped plate 20 and the turbine duct 21 . This second ring-shaped plate 23 covers a part of the outer periphery of the annular member 14 and is bent in the middle, so that the plate 1
By contacting the outer circumferential surface of plate 17, the contact portion between the bead portion of plate 17 and annular member 14 is protected from the outside, and compressed air is prevented from flowing into the scroll passage from the outside through this contact portion. .

As explained above, the relationship between the turbine nozzle and the turbine duct in this embodiment is that the turbine nozzle 6 and the turbine duct 21 are separated, rather than having two functions in one part as in the conventional case. The turbine nozzle 6 is fixed to the compressor body 4, the turbine duct 21 is fixed to the exhaust diffuser 16 on the engine body side, and the turbine nozzle 6 is fixed to the leaf spring 1.
3. It is configured to elastically contact the turbine duct 21 via the annular member 14 and the piston ring 22.

Therefore, the thermal strain of the turbine nozzle 6 itself that occurs during engine operation is absorbed by the displacement of the leaf spring 13 itself, as shown in FIG. 3 before deformation due to thermal strain (dashed line) and during deformation (solid line). Furthermore, the influence of the piston ring 22 is further reduced as the piston ring 22 moves in and out of the groove. This means that the turbine duct 21 itself is not easily displaced even if there is thermal strain in the turbine nozzle 6, and therefore the gap between the turbine blades 2 of the turbine rotor 1 and the inner peripheral surface of the turbine duct 21 is set to an appropriate value. Therefore, the fear of interference with the rotation of the rotor is eliminated.

In addition, the mounting structure of the turbine nozzle 6 according to this embodiment is not a rigid mounting structure in which the outer periphery is fixed to a scroll or the like and the inner periphery is fixed to the compressor body, as shown in FIG. Because it is fixed in a so-called cantilever (floating) type, which is fixed to the compressor body only on the inner circumference side, the turbine nozzle itself will not crack due to uneven loads due to thermal strain, and its durability is extremely high. and improve.

[0022]

As explained above, according to the present invention, the turbine duct is separated from the turbine nozzle, and both parts are fixed to separate parts, so that the thermal strain of the turbine nozzle is directly transferred to the turbine. The duct is not tilted, thermal strain itself is absorbed by the elastic means provided between the two, and the turbine duct and turbine rotor do not come into contact, ensuring smooth rotor rotation.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a turbine rotor portion of a turbine duct mounting structure of the present invention.

FIG. 2 is a partially enlarged view of FIG. 1;

FIG. 3 is a diagram showing a turbine nozzle and its vicinity in which thermal strain has occurred due to a temperature difference during engine operation in the turbine duct mounting structure of the present invention.

FIG. 4 is a sectional view of a turbine rotor portion of a conventional gas turbine engine corresponding to FIG. 1;

[Explanation of symbols]

1... Turbine rotor 4... Compressor body 5... Bearing housing 6... Turbine nozzle 16... Leaf spring (elastic means) 19... Exhaust diffuser (engine body side) 21... Turbine duct 22... Piston ring (elastic means)

Claims (1)

[Claims] 1. A turbine nozzle disposed close to a turbine rotor of a gas turbine engine on the combustion gas upstream side thereof and a turbine duct surrounding the turbine rotor are separated, and the turbine nozzle is fixed to a compressor main body side, A turbine duct mounting structure for a gas turbine engine, in which a turbine duct is fixed to an engine main body side, and the turbine nozzle and the turbine duct are brought into contact engagement via elastic means.